Therapeutic Effects of Minocycline Pretreatment in the Locomotor and Sensory Complications of Spinal Cord Injury in an Animal Model

Spinal cord injury (SCI) is known as a debilitating condition which usually occurs due to traumas to the spine. However, the injury could also occur during clinical interventions such as spinal deformity and thoracoabdominal aortic surgeries. Intraoperative cord compression and ischemia are considered the mechanisms of primary injury in this regard. In the current study, we aimed to evaluate the therapeutic effects of minocycline, a promising agent for post-injury treatment, prophylactic administration. In a rat model of SCI through contusion injury, T9 vertebra laminectomy was performed on 40 Sprague–Dawley male rats provided from Pasteur Institute (Tehran, Iran). The reason behind selecting only male rats in our study was the fact that menstrual cycle of female rats affects healing process. Rodents were divided into a sham-operated group, a control group receiving only saline, a minocycline-treated group, and a minocycline pretreated group. Locomotor scaling, behavioral tests for neuropathic pain, and weight changes were evaluated and compared through a 28-days period. At the end of the study, tissue samples were taken to assess neuroinflammatory cytokine and histopathological changes. Minocycline pretreatment was as effective as its post-SCI administration regarding locomotor activity recovery, mechanical pain, and thermal allodynia. Furthermore, spinal cord inflammation and histopathological alterations were both similar in pretreatment and treatment groups indicating substantially better status. None of the treatments could have completely restore or prevent the spinal cord damage. Minocycline pretreatment can show promising therapeutic effects similar to its post-injury administration, inhibiting inflammatory microglial activity.